Figure 8. Analysis of errors in letter identification
experiment.
Table 1. Percentage of correct
identifications as a function of the number of dots in a
letter. Note that of the 26 letters of the alphabet, a
single letter has 1 dot, five letters have 2 dots, nine
letters have 3 or 4 dots and five letters have 5 dots. |
number of dots in letter |
legibility |
1 |
66.7% |
2 |
63.6% |
3 |
60.2% |
4 |
51.5% |
5 |
43.3% |
Table 2. Distribution of incorrect letter
identifications as a function of the number of dots
incorrectly identified. The second column shows the
distribution that would result from random answers
while the third shows the distribution obtained in
the experiment. For example, 48.1% of the errors
consisted in a single incorrect dot while that
proportion should be 15.7% if answering randomly. |
number of erroneous dots |
probability |
experiment |
1 |
15.7% |
48.1% |
2 |
28.6% |
23.8% |
3 |
29.5% |
17.1% |
4 |
18.8% |
8.0% |
5 |
6.5% |
2.8% |
6 |
0.9% |
0.2% |
|